Apparatus and method for providing coordinated control of a work implement

Abstract

An apparatus and method for providing coordinated control of a work implement of a work machine. The implement includes a boom having a first end portion and a second end portion, with the first end portion pivotally connected to the frame and the second end portion pivotally connected to a load-engaging member. The apparatus includes a position sensor adapted for providing a position signal, and an input device adapted for delivering a desired velocity signal indicative of the desired velocity of the load-engaging member. The desired velocity includes a desired angular velocity and a desired linear velocity. The apparatus receives the position signal and the desired velocity signal, and determines an actual path of travel of the load-engaging member, and a desired path of travel of the load-engaging member. The apparatus further modifies the desired angular velocity and the desired linear velocity in response to a deviation between the actual and desired paths of travel.

What is claimed is:  
     
       1. An apparatus for providing coordinated control of an implement of a work machine having a frame, the implement comprising a boom having a first end portion and a second end portion, with the first end portion pivotally connected to the frame and the second end portion pivotally connected to a load-engaging member, comprising: 
       a position sensor adapted for delivering a position signal;  
       an input device adapted for delivering a desired velocity signal indicative of a desired velocity of the load-engaging member, the desired velocity including a desired angular velocity and a desired linear velocity; and  
       a control system adapted for receiving the position signal and the desired velocity signal, and responsively determining an actual path of travel of the load-engaging member, a desired path of travel of the load-engaging member, a desired velocity ratio, and an actual velocity ratio, the control system being further adapted for modifying the desired angular velocity and the desired linear velocity as a function of the actual and desired velocity ratios in response to a deviation between the actual and desired paths of travel.  
     
     
       2. An apparatus, as set forth in  claim 1 , wherein the control system is adapted for determining an actual velocity of the load-engaging member as a function of the position signal. 
     
     
       3. An apparatus, as set forth in  claim 2 , wherein the control system is adapted for modifying the desired angular velocity and the desired linear velocity in response to both the deviation between the actual and desired paths of travel, and a difference between the desired and actual velocities of the load-engaging member. 
     
     
       4. An apparatus for providing coordinated control of an implement of a work machine having a frame, the implement comprising a boom having a first end portion and a second end portion, with the first end portion pivotally connected to the frame and the second end portion pivotally connected to a load-engaging member, comprising: 
       a position sensor adapted for delivering a position signal;  
       an input device adapted for delivering a desired velocity signal indicative of a desired velocity of the load-engaging member, the desired velocity including a desired angular velocity and a desired linear velocity; and  
       a control system adapted for receiving the position signal and the desired velocity signal, and responsively determining an actual path of travel of the load-engaging member, a desired path of travel of the load-engaging member, an actual velocity of the load-engaging member as a function of the position signal, and an actual angular velocity ratio and an actual linear velocity ratio, the control system being further adapted for modifying the desired angular velocity and the desired linear velocity in response to a deviation between the actual and desired paths of travel,  
       wherein the actual angular velocity ratio is computed by dividing the actual angular velocity by a summation of both an absolute value of the actual angular velocity and an absolute value of the actual linear velocity; and  
       wherein the actual linear velocity ratio is computed by dividing the actual linear velocity by a summation of both an absolute value of the actual angular velocity and an absolute value of the actual linear velocity.  
     
     
       5. An apparatus, as set forth in  claim 4 , wherein the control system is adapted for determining an actual velocity ratio as a function of the actual angular velocity ratio and the actual linear velocity ratio. 
     
     
       6. An apparatus, as set forth in  claim 5 , wherein the control system is adapted for determining a desired angular velocity ratio and a desired linear velocity ratio; 
       wherein the desired angular velocity ratio is computed by dividing the desired angular velocity by a summation of both an absolute value of the desired angular velocity and an absolute value of the desired linear velocity; and  
       wherein the desired linear velocity ratio is computed by dividing the desired linear velocity by a summation of both an absolute value of the desired angular velocity and an absolute value of the desired linear velocity.  
     
     
       7. An apparatus, as set forth in  claim 6 , wherein the control system is adapted for determining a desired velocity ratio as a function of the desired angular velocity ratio and the desired linear velocity ratio. 
     
     
       8. An apparatus, as set forth in  claim 7 , wherein the desired angular velocity ratio and the desired linear velocity ratio are responsively modified based on a difference between the desired velocity ratio and the actual velocity ratio. 
     
     
       9. An apparatus, as set forth in  claim 1 , wherein the input device is adapted for commanding a desired velocity of the boom along a first axis, and a desired velocity of the boom along a second axis, wherein the first axis is perpendicular to the second axis. 
     
     
       10. An apparatus, as set forth in  claim 1 , further comprising: 
       a first actuator associated with the boom;  
       a second actuator associated with the boom; and  
       wherein the control system is adapted for actuating the first actuator and the second actuator as a function of the desired angular velocity and the desired linear velocity, respectively.  
     
     
       11. An apparatus, as set forth in  claim 10 , wherein the first actuator is adapted for controlling an angle of the boom relative to the frame. 
     
     
       12. An apparatus, as set forth in  claim 10 , wherein the second actuator is adapted for controlling a length of the boom. 
     
     
       13. An apparatus, as set forth in  claim 10 , wherein each of the first and second actuators includes a hydraulic cylinder. 
     
     
       14. An apparatus, as set forth in  claim 1 , wherein the position sensor includes at least one of an angle sensor adapted for sensing an angle of the boom relative to the frame, a length sensor adapted for sensing a length of the boom, and an inclination sensor adapted for sensing an angle of inclination of the frame relative to a reference plane. 
     
     
       15. An apparatus, as set forth in  claim 14 , wherein the boom includes a telescopic member movable between a fully retracted length and a fully extended length, wherein the length sensor is adapted for sensing a length of the telescopic member. 
     
     
       16. An apparatus, as set forth in  claim 1 , wherein the input device includes a control lever. 
     
     
       17. An apparatus, as set forth in  claim 1 , wherein the input device includes a joystick. 
     
     
       18. An apparatus, as set forth in  claim 1 , wherein the input device is located on the work machine. 
     
     
       19. An apparatus, as set forth in  claim 1 , wherein the input device is located remote from the work machine. 
     
     
       20. An apparatus, as set forth in  claim 1 , wherein the control system is located remote from the work machine, the control system being adapted for receiving the boom position signal and the desired boom velocity signal through a wireless communication link. 
     
     
       21. An apparatus, as set forth in  claim 1 , wherein the load-engaging member includes a fork. 
     
     
       22. An apparatus, as set forth in  claim 1 , wherein the load-engaging member includes a bucket. 
     
     
       23. A method for providing coordinated control of an implement of a work machine having a frame, the work implement comprising a boom having a first end portion and a second end portion, with the first end portion pivotally connected to the frame and the second end portion pivotally connected to a load-engaging member, comprising the steps of: 
       sensing a position of the load-engaging member, and responsively delivering a position signal;  
       delivering a desired velocity signal indicative of a desired velocity of the load-engaging member, the desired velocity including a desired angular velocity and a desired linear velocity;  
       determining a desired velocity ratio as a function of said desired velocity;  
       determining an actual path of travel of the load-engaging member as a function of the position signal;  
       determining a desired path of travel of the load-engaging member as a function of the desired velocity signal; and  
       modifying the desired angular velocity and the desired linear velocity as a function of said desired velocity ratio in response to a deviation between the actual and desired paths of travel.  
     
     
       24. A method, as set forth in  claim 23 , further including the step of determining an actual velocity of the load-engaging member as a function of the position signal. 
     
     
       25. A method, as set forth in  claim 24 , further including the step of modifying the desired angular velocity and the desired linear velocity in response to both the deviation between the actual and desired paths of travel, and a difference between the desired and actual velocities of the load-engaging member. 
     
     
       26. A method, as set forth in  claim 24 , further including the steps of: 
       determining an actual angular velocity ratio and an actual linear velocity ratio; and  
       determining a desired angular velocity ratio and a desired linear velocity ratio.  
     
     
       27. A method for providing coordinated control of an implement of a work machine having a frame, the work implement comprising a boom having a first end portion and a second end portion, with the first end portion pivotally connected to the frame and the second end portion pivotally connected to a load-engaging member, comprising the steps of: 
       sensing a position of the load-engaging member, and responsively delivering a position signal;  
       delivering a desired velocity signal indicative of a desired velocity of the load-engaging member, the desired velocity including a desired angular velocity and a desired linear velocity;  
       determining an actual path of travel of the load-engaging member as a function of the position signal;  
       determining an actual velocity of the load-engaging member as a function of the position signal;  
       determining a desired path of travel of the load-engaging member as a function of the desired velocity signal;  
       determining an actual angular velocity ratio by dividing the actual angular velocity by a summation of both an absolute value of the actual angular velocity and an absolute value of the actual linear velocity and an actual linear velocity ratio by dividing the actual linear velocity by a summation of both an absolute value of the actual angular velocity and an absolute value of the actual linear velocity;  
       determining a desired angular velocity ratio by dividing the desired angular velocity by a summation of both an absolute value of the desired angular velocity and an absolute value of the desired linear velocity and a desired linear velocity ratio by dividing the desired linear velocity by a summation of both an absolute value of the desired linear velocity and an absolute value of the desired angular velocity; and  
       modifying the desired angular velocity and the desired linear velocity in response to a deviation between the actual and desired paths of travel.  
     
     
       28. A method, as set forth in  claim 27 , further including the steps of: 
       determining an actual velocity ratio as a function of the actual angular velocity ratio and the actual linear velocity ratio; and  
       determining a desired velocity ratio as a function of the desired angular velocity ratio and the desired linear velocity ratio.  
     
     
       29. A method, as set forth in  claim 28 , further including the step of modifying the desired angular velocity ratio and the desired linear velocity ratio in response to a difference between the desired velocity ratio and the actual velocity ratio. 
     
     
       30. A method, as set forth in  claim 23 , further comprising the step of actuating a first actuator and a second actuator as a function of the desired angular velocity and the desired linear velocity, respectively. 
     
     
       31. A method, as set forth in  claim 23 , wherein sensing the position of the load-engaging member includes the steps of: 
       sensing an angle of the boom relative to the frame;  
       sensing a length of the boom; and  
       sensing an angle of inclination of the frame relative to a reference plane.